CHICAGO -- Cubs infield coach Ivan DeJesus met with shortstop Starlin Castro on Tuesday. The message? Be prepared.

Castro committed three errors in one inning, which led to three unearned runs, on Monday against the Rockies

"He knows he didn't have a real good night, and we know he's not going to have a lot of nights like that," Cubs manager Mike Quade said. "We all make mistakes. They got bunched up and that's tough, but he'll be fine. I'm not an excuse maker, but it wasn't a great night to play."

Both teams had to deal with rain, wind and cold at Wrigley Field. The Rockies were outhit, 11-4, but won the game, 5-3.

DeJesus told Castro he needs to be better prepared.

"I think he was a little late [on a couple of the plays]," DeJesus said. "Sometimes on wet grass, you have to slow things down. He's learning every day."

Castro was back in the leadoff spot on Tuesday, where he'd hit .500 (23-for-46). He's now 2-for-17 in the No. 3 hole. Quade said he hasn't noticed a change in Castro's approach.

"Look, we think this guy is a pretty important part of our future," Quade said of the 21-year-old shortstop, the youngest player in the Major Leagues. "I have no concerns about his psyche no matter where he hits. If he showed up tomorrow and was hitting fourth, I don't think he'd blink.

"We're looking for a three-hole hitter and we're looking for one for [the long term]," Quade said. "I want to find out. He's going to lead off today, and we'll go back and forth with left-handers and right-handers in our lineup [against Rockies left-hander Jorge De La Rosa].

"He's talented and capable and going through the first month of our season. He's our best hitter and that's supposed to be your third guy. We'll see how it plays out."

Castro has shown he can hit. He also needs to show he can handle shortstop. Both starting pitcher Matt Garza and second baseman Darwin Barney shouldered blame for Monday's loss, deflecting some of the focus off Castro. Quade liked hearing that. It doesn't mean Castro shouldn't learn from his mistakes.

"He has to play defense every day," DeJesus said.

Pena battling to find offensive rhythm

CHICAGO -- This was not how Carlos Pena wanted to start the season with the Cubs.

The first baseman, coming off a .196 season, has had to deal with a right thumb injury and tough weather conditions that have been knocking down potential home runs at Wrigley Field.

"Things are not the way I would want it to be so far, and I've been disappointed with the start," said Pena, who is batting .169 overall and 2-for-21 in seven games on the homestand.

"At the same time, I always try to make the best out of every situation," he said. "That may not seem rational for everyone to think that way, but for me it's the only way. Even though things haven't gone as well as I've liked, I know it's early."

He had one extra-base hit in his first 59 at-bats entering Tuesday's contest against the Rockies. That's not much of a sample size. Pena, 1-for-13 against lefties this year, was not in the lineup Tuesday against lefty Jorge De La Rosa. Pena's also struggling with runners on, batting .114. With runners in scoring position, he's hitting .150.

Jeff Baker began the day hitting .400 overall and .455 against lefties, and he started Tuesday at first base. Cubs manager Mike Quade said he isn't using a platoon system with Baker and Pena; He's just trying to get Baker in the lineup.

Pena won't make excuses, so you won't hear him blame the frigid weather or the sprained thumb. He's focusing on the positives. Maybe all he needs is a home run. He's come close in a few at-bats.

"I have to be so mentally tough, there's no doubt about it," Pena said. "I have pride. I enjoy this game. I have teammates I want to come through for -- they're always there for me, which I appreciate. I've had to deal with some adversity early on with the finger, the weather, but I try not to pay attention to 'Why, why, why hasn't it happened?'"

He knows there are critics. He ignores them.

"That's the way I choose to look at it even though it's not always easy," Pena said. "I'm human, too. I get upset, I get frustrated, but then I take a deep breath and say, 'Let's look at the reality' and don't give into the illusion."

Extra bases

• The toughest decision these days for Cubs manager Mike Quade is trying to get Jeff Baker in the lineup. Baker started at first on Tuesday. "His versatility makes a huge difference," Quade said of Baker, who has started at first, third and second. "He's swinging the bat so well."

• It took Quade a little time to calm down after Monday's 5-3 loss to the Rockies. "You get mad -- so what are you going to do about it?" he said. "Getting mad doesn't help."

• Pitchers Andrew Cashner and Randy Wells, both on the disabled list, threw on flat ground Tuesday. They are scheduled to be examined by team orthopedic specialist Dr. Stephen Gryzlo on Wednesday. Cashner is sidelined with a strained right rotator cuff; Wells has a strained right forearm. There's no timetable for their returns.

• Kosuke Fukudome is the fifth Cubs leadoff man since 1986 to have five hits in a game, joining Ryan Theriot (April 25, 2010), Alfonso Soriano (May 17, 2008; June 4, 2007), Tom Goodwin (July 21, 2003), and Davey Lopes (April 20, 1986).